Well, you can check mail order, but shipping 5 Gal would not be cheap. That's not a high price here for the size--5 gal is fairly big and represents some prolonged maintenance by the nurseries that keep their own stock; but if you're trying to match the size you've got, you may want to go for it. Or, get a bit smaller one and give it lots of TLC--mine have grown substantially in 3 yrs.

This combo may not be relevant in your zone, but I'm trying some dwarf variegated euonymus in front of some Shishi's--it's green and white and develops pink tones in cold weather when the Shishi blooms, and looked good when I had the potted items together. It may turn out to flop or ramble too much, though). I'm trying that and another type of variegated shrub with white in it, which stands out against the dark Shishi foliage background for the year and then is pretty with the hot pink flowers. So if say, variegated pittosporum grows in your climate, or something similar, that can make a nice combo with dark broadleaved evergreens like camellias.

Other camellias that "go with" depend on whether you have a particular symmetry or repetition in your garden that you're trying to achieve with more of the same variety, versus whether other camellias actually bloom at the same time and need to not clash (mainly orangey-red with some of the pinks, though camellia color combinations are fairly forgiving) , or whether you are trying to include several types of camellias to bloom at a bit different times on purpose to extend flowering, or aren't right next to each other. Shishi is particularly good as a low-growing type, and not too many are like that (see a recent thread with some suggestions), so there are places I can use it where I could not use another variety--most others will be much more upright and get tall. So if I don't have height limitations, I will use taller varieties in order to satisfy my collecting cravings. Or if you can make a deep enough bed, Shish can be at the foot of a taller variety.